The approaches described herein provide an efficient way to process certain kinds of queries that retrieve XML data stored in an object-relational database. The first and second portions are coupled by a bendable coupling. The result of comparison is frequency divided to generate a frequency divided signal; and the switching control signal is generated in response to the frequency divided signal. The sensor members can sense a positional variation of the rear-view mirror and send a feedback signal to the servo control circuits. Additionally provided is a nanocomposite material containing intercalated FeF2\u2014 or Fe2O3\u2014 nanoparticles in a graphitic carbon matrix and its use as an electrochemically active material in particular for use in electrochemical storage cells.